An iterative condensation method for large-scale finite element model with damping

Aiming at structural systems with dampers, this paper presents a new iterative method for dynamic condensation of large scale finite element (FE) models. Firstly, the mass matrix, stiffness matrix and damping matrix are extracted from the FE model of the system, and rewritten in a partitioned form according to the order of the master and slave degrees of freedoms. Secondly, the governing equation of the condensation matrix with damping is constructed based on the equivalent relationship of the coefficient matrix as to the same master degrees of freedom, and then be solved to get the required matrix with an iterative procedure. Finally, the reduced FE model is obtained by using the condensation matrix. During the procedure of model reduction, the adjusting of the system matrices in a sequence is simple, and the derivation of the linear transformation matrix is also convenient. Furthermore, the mass, damping and stiffness matrices of system have explicit forms. The results of numerical examples demonstrate the validity and effectiveness of the presented method.